Multi-mode optical fiber is a type of optical fiber mostly used for communication over shorter distances, such as within a building or on a campus. Typical multimode links have data rates of 10 Mbit/s to 10 Gbit/s over link lengths of up to 600 meters—more than sufficient for the majority of premises applications. The equipment used for communications over multi-mode optical fiber is much less expensive than that for single-mode optical fiber. Typical transmission speed/distance limits are 100 Mbit/s for distances up to 2 km, 1 Gbit/s to 500-600 m, and 10 Gbit/s to 300 m.
Multimode fiber has higher “light-gathering” capacity than single-mode optical fiber. In practical terms, the larger core size simplifies connections and also allows the use of lower-cost electronics such as light-emitting diodes and vertical-cavity surface-emitting lasers which operate at the 850 nm wavelength (single-mode fibers used in telecommunications operate at 1310 or 1550 nm and require more expensive laser sources. Multimode fibers exist for nearly all visible wavelengths of light). However, compared to single-mode fibers, the limit on speed times distance is lower. Because multimode fiber has a larger core-size than single mode fiber, it supports more than one propagation mode; hence it is limited by modal dispersion, while single mode is not.